Mastering Linux printf: Formats, Escape Sequences, and Real-World Examples

When writing shell scripts, echo can only print simple text, while printf offers full control over output formatting, making it the preferred command for structured data.

The general syntax is printf format [arguments...], where the format string contains conversion specifiers such as %s for strings and %d for decimal integers, and literal characters like \n for newlines must be added manually.

Example – printing personal information :

printf "姓名：%s
身高：%dcm
体重：%dkg
" "小明" "180" "75"
# Output:
姓名：小明
身高：180cm
体重：75kg

Common escape characters : \" – escaped double quote \\ – escaped backslash \b – backspace \n – newline \r – carriage return \t – horizontal tab \v – vertical tab %% – literal percent sign

Common conversion specifiers : %d – decimal integer %f – floating‑point number %s – string %x – hexadecimal integer %o – octal integer

Example 1 – numeric bases :

printf "Decimal: %d
Hex: %x
Octal: %o
" 100 100 100
# Output:
Decimal: 100
Hex: 64
Octal: 144

Example 2 – floating‑point precision :

printf "%.2f
" 3.1415926
# Output:
3.14

Example 3 – tabular output with extra arguments :

printf "%s \t %s \t %s
" "姓名" "性别" "年龄" "小明" "男" "18" "小红" "女" "19" "小蓝" "男" "18"
# Output:
姓名   性别   年龄
小明   男   18
小红   女   19
小蓝   男   18

Example 4 – field width, alignment, and color :

# Left‑aligned fields (width 10)
printf "\e[1;30;47m%-10s %-10s\e[0m
" "姓名" "年龄"
# Colored rows with specific widths
printf "\e[36;47m%-10s %-8d\e[0m
" "小明" 18
printf "\e[31;47m%-10s %-8d\e[0m
" "小红" 19
printf "\e[34;47m%-10s %-8d\e[0m
" "小蓝" 19

These examples demonstrate how printf can format text, numbers, and colors precisely, making it a powerful tool for producing readable command‑line output.

End of tutorial.